Terminal structure for refrigerating apparatus



March 30, 1948. A. A. MccoRMAcK 2,438,572

TERMINAL STRUCTURE FOR REFRIGERATING APPARATUS Filed May 11, 1944 INVENTOR.

BY 5 j m 7 2%,

Patented Mar. 30,

TERMINAL STRUCTURE FOR REFRIGERAT- ING APPARATUS Alex A. McCormack, Cleveland, iOhio, assignor to General Motors Corporation, 4llayton, Ohio, a corporation of Delaware f/ Application May 11, 1944, Serial No. 535,066

6 Claims. 1

This invention relates to refrigeratlng apparatus and more particularly to an improved electric terminal assembly for use in a sealed motorcompressor unit.

Terminals of the type which have been used satisfactorily by the millions in ordinary household refrigerators have proven very unsatisfactory when used in large sealed commercial units using higher refrigerant pressures and higher voltages. Attempts to modify the prior art type of terminals for us-e in the larger systems merely increased the cost of the terminals without elimihating frequent failures. Prior to my invention, the electric terminal assembly was one of the expensive items of a sealed motor-compressor unit and was also one of the main causes of service difficulties.

It is an object of this invention to not only reduce the cost of the terminal assembly but also to improve upon the reliability of the terminal assembly.

A further object of this invention is to provide a terminal construction which combines the advantages of a terminal using a vulcanized sealing element with the advantages ci a terminal in which pressure is applied to the sealing element for providing a tight seal.

Another object of this invention is to improve the construction of the terminal so that pressure may be applied to a synthetic rubber sealing material while the synthetic rubber is being vulcanized to the metallic terminal studs and mounting plate.

A further object of this invention is to provide a multiple terminal assembly wherein all of the terminals are vulcanized in place in a single operation.

A still further object of this invention is to provide an improved terminal assembly in which a singler means is provided for connecting the leads to the terminals and for applying pressure to the sealing material.

Another object ofthis invention is to provide a terminal assembly in which the main portion of the terminals are well protected from injury during shipment and the like. l

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown. A

In the drawings:

Fig. 1 is a sectional view taken on line I-l of Fig. 2;

Fig. 2 is a Plan view of the terminal construction shown in Fig. 1.

Referring now to the drawing wherein I have shown a preferred embodiment of the invention, reference numeral I0 designates a terminal plate which is hydrogen brazed or otherwise secured to a'stamped sheet metal mounting cup I2. Reference numeral I4 designates a cylindrical element which is welded to the cup l2 adjacent the upper edge of the cup i2 whereby a iiuid tight joint is formed between the cup l2 and the cylindrical element I4. The element i4 is welded to the motor-compressor casing i6 at I8 whereby a fiuid tight joint is provided between the casing l5 and the cylindrical element i4. The construction and arrangement of the elements l0, l2 and l may be varied somewhat without defeating the main purpose of my invention.

Prior to welding the element i4 to the casing i6, a plurality of terminal studs 2@ are vulcanized in place relative to the terminal plate l0 by means of the synthetic rubber material 22. The terminal studs 2G are of very simple construction and may be made on ordinary automatic screw machine equipment with the result that the cost thereof is very low. The construction and arrangement of the terminal studs 2li and the terminal plate i@ issuch that a portion of the synthetic rubber material is required to flow between the bottom face of the terminal plate l!! and the upper face of the flange 2f'. provided on the terminal stud 2li. By virtue of this construction, pressure may be applied to the synthetic rubber between the flange 2d and the terminal plate i9 during the vulcanizing process whereby a very good vulcanized joint is provided. It has been found that a joint in which pressure is applied in this manner during the vulcanizing operation is very superior to other types of vulcanized joints.

In the construction shown, the synthetic rubber between the upper ends of the terminal studs 20 and the apertures in the terminal plate l@ serves to insulate the terminal studs from the plate. It will be noted that a portion of the synthetic rubber overlies the upper face of the terminal plate itl adjacent each aperture as shown at 25. A block of insulation 3@ is' held in place against the synthetic rubber at ES whereby arcing` across the terminals is prevented. The block 3U forms a contact mounting member or means and carries suitable conducting elements such as the elements 32 which are used for electrically connecting various terminals. Lead wires are connected to certain of the terminals by means'ot some of the screws 34 which help to hold the block 30 in place and which serve to pull the flanges 24 of the terminal studs 20 closer to the plate I whereby the synthetic rubber material between the anges and the plate lll is compressed so as to more securely seal the openings in the plate l0 through which the terminals pass.

Inorder to standardize on the motor constructions'and in order to make it possible to connect the same motor to diierent types of power lines without disturbing the internal connections, nine terminals are provided as shown whereby ythe various iield coils of the motor (not shown) may be connected in any desired manner merely by changing the external contacts or connections carried by the contact mounting member or block ber of terminals may be used.

It will be noted that the terminal studs 20 do not project far enough beyond the outer face of the plate I0 that there is any danger of them becoming injured after once the plate is mounted on the casing I6. It will also be noted that the terminal studs 2i) do not project upwardly as high as the overlying portion 25 of the synthetic rubber insulating material. Notwithstanding the simplicity of the device, it incorporates excellent insulating barriersv `between the terminals and ground and between adjacent terminals. The device also lends itself to low cost mass production methods.

While the form of embodiment of the inven- 3U. While I have shown nine terminals, any numtion as herein disclosed constitutes a Jreferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claims which follow.

What is claimed is as follows:

l. In combination, a casing having an opening therein, a terminal assembly mounted within said opening, said terminal assembly comprising a terminal plate having a plurality of terminal receiving apertures therein, a 'plurality of terminal studs within said casing and projecting into said apertures, said terminal studs havingtapped recesses exposed on the outer side of said plate, flanges on said terminal studs overlying the inside face of said terminal plate, synthetic rubber gasket material disposed between said anges and said plate and vulcanized to said flanges and said plate, said gasket material extending through said apertures and overlying portions of the outside face of said terminal plate, a contact mounting member of insulating material having a plurality of apertures in alignment with said tapped recesses, and threaded terminal screws projecting through said last-named apertures andinto said tapped recesses whereupon tightening said terminal screws compresses the synthetic rubber gasket between said flange and said terminal plate.

2. In combination, a terminal plate having a plurality of apertures therein, a mounting cup.

ing barrier between said terminal studs and saidterminal plate, said anges being embedded in said synthetic rubber.

3. An electrical terminal assembly adapted to conduct electrical energy through a wall of a container comprising in combination, terminal supporting means including a terminal supporting plate having a plurality of apertures therein, terminal studs in alignment with said apertures and having flanges thereon larger than said openings and spaced from said plate, resilient material vulcanized to said ilanges and said plate and serving to space said flanges from said plate, said studs having tapped openings in the outer ends thereof for the reception of terminal screws from the outside of said container, the outer ends oi" said terminal studs being disposed below the outer surface of said terminal supporting means so as to be protected from injury by said terminal supporting means, a portion of said resilient material extending onto the outer face of said plate, a block of insulating material adjacent the outer face ofsaid plate in contact with said resilient material which extends onto the outer face of said plate, conducting elements carried by said block of insulating material for electrically connecting certain of said terminal studs, and terminal screws connected to certain of said studs and serving to hold said insulating block against said resilient material.

4. In combination, a terminal plate having a terminal receiving aperture therein, a terminal stud projecting into said aperture, said terminal stud having a tapped recess exposed on the one side of said plate. a iiange on said terminal stud overlying the inside face of said terminal plate,

gasket material disposed between said ange and said plate and vulcanized to said ilange and said plate, said gasket material extending through said apertureand overlying portions of the face of said terminal plate, a contact mounting member overlying said terminal plate and having an aperture in alignment with said tapped recess, a threaded terminal screw projecting through said last-named aperture and into said tapped recess whereupon tightening said terminal screw compresses the gasket material between said ange and said terminal plate.

5. In combination, a casing having an opening therein, a terminal assembly mounted within said opening, said terminal assembly comprising a terminal plate having a plurality of terminal receiving apertures therein, a, plurality of terminal studs within said casing and projecting into said apertures, each of said terminal studs having a tapped recess exposed von the one side of said plate, a flange on each of terminal studs overlying the inside face ofvsaid terminal plate, gasket material disposed between said flanges and said plate and vulcanized to said flanges and said plate, said gasket materialextending through' said apertures and overlying portions of the outside face of said terminal plate, apertured contact mounting means overlying said terminal plate, and terminal screws projecting through said apertured Contact mounting means and into said tapped recess whereupon tightening said terminal screws compresses the gasket between said flange'and said terminal plate.

6. An electrical terminal assembly adapted to conduct electrical energy through a wall of a container comprising in combination, a terminal supporting plate having a, plurality of apertures therein, terminal studs in alignment with said apertures and having flanges thereon larger than said openings and spaced from said plate, resilient material vulcanized to said flanges and said plate and serving to space said flanges from said plate, said resilient material extending through 5 said apertures and overlying portions of the outside oi said terminal plate, said studs having tapped openings in the outer ends thereof for the reception. of terminal screws from the outside of said container. the outer ends of said terminal studs being disposed below the outer surface of said resilient material which overlies said terminal supporting plate so as to be protected from injury.

ALEX A. MCCORMACK.

REFERENCES CITED Number UNITED STATES PATENTS Name Date Amon Feb. 29, 1916 Dodgson Sept. 27, 1921 Brown June 24, 1930 Polivka. Oct. 24, 1939 Borchert Dec. 9, 1941 Bailey Jan. 5, 1943 Anderson et al Apr. 6, 1943 Kalstein Jan. 30, 1945 

